Expander apparatus



May 13, 1969 R. E. ROPER EXPANDER APPARATUS Sheet of 5 Filed June 7, 1967 May I3, 1969 R. E. ROPER 3,443,413

` EXPANDER APPARATUS I Filed June v, 1967 sheet 2 of 5 INVENTOR. RALPH E. RoPER.

i of 5 Shee'fI Filed June '7, 1967 INVENTOR RALPH E. ROPE/fa United States Patent O 3,443,413 EXPANDER APPARATUS Ralph E. Roper, Indianapolis, Ind., assignor to Wallace Expanding Machines, Inc., Indianapolis, Ind., a corporation of Indiana Filed June 7, 1967, Ser. No. 644,250 Int. Cl. B213' 7/16; B21d 31/00, 41/00 U.S. Cl. 72-399 9 Claims ABSTRACT OF THE DISCLOSURE Background of invention Field of th'e inventi0n.-This invention relates to apparatus, such as piercing apparatus and expander apparatus, for forming metallic sheet and the like into parts.

Description of the prior art.Wallace Expanding Machines, Inc., assignee of the present application, manufactures expanders for a number of dilferent applications such as forming of automobile fenders, doors, and bonnets and washing machine tubs to mention only a few. Such an expander is shown, for example, in the U.S. patent to Roper, 3,254,521, and includes a set of inner dies which are expanded within a tubular metal workpiece causing the workpiece to stretch over the inner dies to form the desired configuration. If inwardly directed indentations are desired in the workpiece, it is necessary to also provide outer dies which are xed in position and against which the inner dies force to form inwardly directed indentations in the workpiece.

There are other types of metal forming apparatus which operate similarly to the above described expanders in that both inner and outer dies are provided, the workpiece is tubular and the inner dies expand against the outer dies with the tubular workpiece between the inner dies and outer dies. One such apparatus is a piercing apparatus which operates to pierce holes or apertures through the walls of a tubular workpiece.

In such metal forming apparatus it is necessary to provide means for moving the outer dies inwardly to the position at which they are ixed for forming by the inner dies. After the part has been formed, it is necessary to move the outer dies away from the part so that the part can be removed from the expander. In the device of the Roper patent this is accomplished by an outer cam ring which not only moves the outer dies between their inward and outward position but also locks them at their inward position. Such a cam ring and its associated operating structure is expensive and ditiicult to manufacture. Consequently, there exists a need to provide less expensive but just as efficient means to move the outer dies inwardly and outwardly and to lock the outer dies at their inward position.

Summary of the invention One embodiment of this invention might involve metal forming apparatus comprising a frame, at least a pair of outer die carriers, at least a pair of tracks arranged at an angle to one another and guiding said outer die carriers inwardly and outwardly, said outer die carriers mov- ICC ing closer to one another when moving inwardly and farther apart from one another when moving outwardly, a fluid cylinder fixed to one of said die carriers and having a piston rod secured to the other of said die carriers, said cylinder and piston rod being arranged to exert a force pulling said die carriers together when said piston rod is retracted by said cylinder and to exert a force moving said die carriers apart when said piston rod is projected by said cylinder.

One object of this invention is to provide an improved expander apparatus.

Another object of this invention is to provide improved metal forming apparatus.

A further object of this invention is to provide improved relatively inexpensive means in metal forming apparatus for moving outer dies and locking them in position.

Related objects and advantages will appear as the description proceeds.

Brief description of the drawing FIG. l is a top plan View with portions thereof broken away of expander apparatus embodying the present lnvention.

FIG. 2 is a reduced size View similar to FIG. 1 -but showing the apparatus in a different operating position.

FIG. 3 is a vertical section taken along the line 3--3 of FIG. l in the direction of the arrows.

FIG. 4 is a top plan -view of the apparatus of FIGS. 1, 2 and 3 but additionally showing inner dies and associated structure together with a workpiece operated on by the present apparatus.

FIG. 5 is a vertical section taken along the line 5-5 of F IG. 4 in the direction of the arrows.

Description of the preferred embodiments Referring now more particularly to the drawings and to FIGS. 4 and 5, there is illustrated an expander apparatus 10 which includes an inner die assembly 11 and an outer die assembly 12. The inner die assembly 11 is made up of inner die carriers 15, upon which are mounted inner dies 16, as well `as a wedge 17 which is keyed to the inner die carriers 15 by means of keys 20.

The wedge 17 can be moved upwardly by the piston rod 21 so as to cause the die carriers 15 to move inwardly to the position as shown in FIGS. 3 and 4. In this position the workpiece 22 can be slipped over the inner die assembly 11 to the position shown in FIGS. 3 and 4. The piston rod 21 can be moved downwardly causing the wedge 17 to force against the die carriers 15 and to move the die carriers outwardly, in which case the workpiece 22 is expanded and forced against the outer dies 26 which form a part of the outer die assembly 12.

Thus, the general operation of the expander disclosed herein is the same as the general operation of the expander disclosed in the above mentioned Roper patent wherein FIG. l shows the operating position illustrated in FIG. 4 of the present application and FIG. 4 of the Roper patent shows the expanded position of the inner die `assembly with the workpiece in its expanded position between the outer dies and the inner dies.

In order to make possible such a forming operation, it is necessary that the outer dies be movable inwardly and outwardly and also that they be capable of being fixed in the inward position so`that the inner dies can then be expanded against the outer dies. Referring to FIGS. l, 2 and 3, the present expanding apparatus is shown with the inner die assembly removed for clarity. The outer die assembly 12, as well as the inner die assembly 11, is slidably mounted upon a frame 30. The frame 30 includes an upper plate 31, a lower plate 32 and four posts 35 which connect these plates.

Fixedly mounted upon the upper and lower plates are tracks 36. There are four such tracks provided for each outer die carrier 40 with two of the tracks for each outer die carrier being mounted on the lower plate 32 and two of the tracks being mounted on the upper plate 31. Each outer die carrier 40 has tixedly mounted thereon four guide members 41 which are positioned to extend into the recesses 42 provided in the tracks 36.

Not only do the outer die carriers ride within the tracks 36 on the top plate 31 and the bottom plate 32 but they also are guided by bearings 45 mounted on the posts 35. Four of the bearings 45 are provided for each outer die carrier 40, each of which has four grooves 44 receiving the bearings 45. Each of the outer die carriers 40 has also tixed thereon pads 46 which engage the pads 46 of the adjacent outer die carriers when the outer die carriers are in the inward position of FIG. l.

Four fluid cylinders 50 are mounted on two of the outer die carriers 40 and have piston rods 51 which are connected to the other two die carriers 40. In order to move the outer die carriers 40 outwardly to the position of FIG. 2, the tluid cylinders are caused to simultaneously project their piston rods 51, causing a pair of forces to be exerted on each outer die carrier 40, the resultant of which is directed outwardly parallel to the tracks 36. In other words, each piston for each cylinder 50 exerts a force acting upon the outer die carrier to which it is secured, said force acting at a 45 degree angle to the direction of the tracks 36. There are two such forces acting on each outer die carrier and the resultant of those two forces is parallel to the direction of the tracks 36. Also, because of the fact that the cylinders are symmetrically mounted on the outer die carriers 40, the resultant force acts directly through the center of the outer die carriers.

When the fluid cylinders 50 are operated to simultaneously retract their piston rods 51, forces are caused to act in the opposite direction to that described above, said opposite forces being also in the direction of the tracks 36. Thus, the outer die carriers 40 move inwardly to the position illustrated in FIG. 1 wherein the pads 46 abut. It is necessary that the outer die carriers 40 be locked in the position of FIG. l. This is accomplished by four iuid cylinders 55, each of which has a piston 56 pivoted to a block 57. Each of the cylinders 55 itself is fixed to a respective blocking member 60 which is slidably mounted on a respective outer die carrier by means of guide members 61 and screws 62.

Each block 57 is secured by screws 65 to a respective blocking member 66 which is slidably mounted upon a respective die carrier 40 by guide members 67 and screws 70. The blocking members 60 Iand 66 are limited in their travel by members 71 which are iixed to the outer die carriers 40 and which project into recesses 72 in the blocking members 60 and 66. When the blocking members 60 and 66 are projected, the blocking members project into recesses 75 and 76 in the bottom plate 32 and the top plate 31. Mounted in the recesses 75 and 76 are abutments 80. The abutments 80 operate to block the blocking members from moving outwardly and thus lock the outer die carriers 40 in the illustrated inward position of FIGS. 1 and 3.

It will be evident from the above description that the present invention provides an improved expander apparatus and provides an improved metal forming aparatos usable not only in expanders but also in other apparatus such as piercing apparatus. It will also be evident that the present invention provides improved relatively inexpensive means for moving the outer die assembly and for locking it in the inward position.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all 4 changes and modifications that come within the spirit of the invention and the scope of the claims are also desired to be protected.

The invention claimed is:

1. Metal forming apparatus comprising a frame, at least a pair of outer die carriers, at least a pair of tracks arranged at an angle to one another and guiding said outer die carriers inwardly and outwardly, said outer die carriers moving closer to one another when moving inwardly and farther apart from one another when moving outwardly, a fluid cylinder fixed to one of said die carriers and having a piston rod secured to the other of said die carriers, said cylinder and piston rod being arranged to exert a force pulling said die carriers together when said piston rod is retracted by said cylinder and to exert a force moving said die carriers apart when said piston rod is projected by said cylinder.

2. Metal forming apparatus comprising a frame, a plurality of outer die carriers, a plurality of tracks on said frame each receiving a respective one of said outer die carriers and guiding it through a path inwardly and outwardly of said frame, said outer die carriers being movable inwardly on said tracks to a iirst position in which said outer die carriers are in contact with one another so as to form a closed ring, said outer die carriers being movable outwardly 0n said tracks to a second position in which said outer die carriers are spaced from one another, a plurality of fluid cylinders each being secured to a die carrier and having a piston rod secured to an adjacent die carrier in such a manner that all of said die carriers are connected together in a ring by said fluid cylinders and their piston rods, said fluid cylinders and their piston rods being arranged to exert a force pulling said die carriers together when said piston rod is retracted by said cylinder and to exert a force moving said die carriers apart when said piston rod is projected by said cylinder.

3. The metal forming apparatus of claim 2 wherein said plurality of outer die carriers are four outer die carriers, said uid cylinders being arranged to project and retract in directions which are at 45 degrees to the direction of inward and outward movement of said outer die carriers, a rst opposite pair of said outer die carriers being movable toward and away from one another, and a second opposite pair of outer die carriers being movable toward and away from one another at degrees to the movement of said first opposite pair of outer die carriers.

4. The metal forming apparatus of claim 2 additionally comprising a plurality of pairs of abutments mounted on said frame, the two abutments of each pair of abutments 'being located on opposite sides of the path of a respective outer die carrier, a plurality of pairs of blocking members, a further plurality of -tluid cylinders each mounted on one respective blocking member of each pair and having a piston rod connected to the other blocking member of each pair so that projection of the piston rods of said cylinders moves apart the two block ing members of each pair of blocking members, each of said pairs of blocking members being slidably mounted on a respective outer die carrier and movable by the projection of their respective further cylinder into positions wherein said blocking members are engageable with said abutments to prevent movement of said outer die carriers outwardly from said trst position.

5. The metal forming apparatus of claim 3 additionally comprising a plurality of pairs of abutments mounted on said frame, the two abutments of each pair of abutments being located on opposite sides of the path of a respective outer die carrier, a plurality of pairs of blocking members, a further plurality of iiuid cylinders each mounted on one respective blocking member of each pair and having a piston rod connected to the other blocking member of each pair so that projection of the piston rods of said cylinders moves apart the two blocking members of each pair of blocking members, each of said pairs of blocking members being slidably mounted on a respective outer die carrier and movable by the projection of their respective further cylinder into positions wherein said blocking members are engageable with said abutrnents to prevent movement of said outer die carriers outwardly from said rst position.

6. The metal forming apparatus of claim 4 additionally comprising -outer dies mounted on said outer die carriers, inner dies movably mounted on said frame, means for moving said `inner dies outwardly to act on a workpiece surrounding said inner dies and to force said workpiece against said outer dies.

`7. The metal forming apparatus of claim 6 wherein said plurality of outer die carriers are four outer die carriers, said Huid cylinders being arranged to project and retract in directions which are at 45 degrees to the direction of -inward and outward movement of said outer die carriers, a rst opposite pair of said outer die carriers being movable toward and away from one another, and a second opposite pair of said outer die carriers being movable toward and away from one another at 90 degrees to 6 the movement of said first opposite pair 4of outer die carriers.

8. The metal forming apparatus of claim 7 wherein sixteen of said tracks are provided with four of said tracks being provided for each outer die carrier, eight of said tracks being above said outer die carriers and eight of said tracks being below said outer die carriers.

9. The metal forming apparatus of claim 8 wherein said -means for moving said inner dies comprises a wedge and inner die carriers keyed to said wedge, said inner dies being fixed to said inner die carriers.

References Cited UNITED STATES PATENTS RONALD D. CREFE, Primary Examiner.

U.S. C1. X.R. 

